Examine source code of Safari Adaptive Light

{
  "manifest_version": 2,
  "name": "Safari Adapt Light",
  "version": "2019.1102",
  "description": "Even better with Safari-Theme-for-Firefox: https://git.io/JeBLr",
  "icons": {
    "48": "light48.png",
    "96": "light96.png",
    "256": "light256.png"
  },
  "theme": {
    "colors": {
      "toolbar": "#e7e7e7",
      "toolbar_text": "#575757",
      "frame": "#bebebe",
      "tab_background_text": "#000000",
      "toolbar_field": "#fbfbfb",
      "toolbar_field_text": "#333333",
      "tab_line": "#cecece",
      "popup": "#f1f1f1",
      "popup_text": "#3c3c3c",
      "tab_loading": "#e6e6e6",
      "tab_background_separator": "#7f7f7f",
      "toolbar_top_separator": "#b1b1b1",
      "toolbar_bottom_separator": "#a7a7a7",
      "toolbar_vertical_separator": "#ffffff88",
      "tab_selected": "#d3d3d3",
      "sidebar": "#e5e5e5",
      "ntp_background": "#e5e5e5",
      "sidebar_text": "#2c2c2c",
      "ntp_text": "#2c2c2c",
      "popup_highlight": "#3992f1",
      "popup_highlight_text": "#ffffff",
      "button_background_active": "#fefefe",
      "button_background_hover": "#fefefe",
      "frame_inactive": "#f6f6f6"
    }
  }
}